* H. J. Lu: > Add -mindirect-branch-loop= option to control loop filler in call and > return thunks generated by -mindirect-branch=. 'lfence' uses "lfence" > as loop filler. 'pause' uses "pause" as loop filler. 'nop' uses "nop" > as loop filler. The default is 'lfence'.
Why is the loop needed? Doesn't ud2 or cpuid stop speculative execution?
